Talks to secure the future of the Tri Force Specialist Operations alliance between the Gloucestershire, Wiltshire and Avon and Somerset forces have ended without agreement.

The collaboration, which has been in place since 2012, was seen as a way of providing roads policing, armed response and police dogs “more efficiently by sharing resources”.

A number of independent reviews have since made recommendations to improve the effectiveness of the partnership, highlighting issues such as multiple briefing systems, human resources processes, policies and IT.

However, in a joint statement issued on Tuesday (November 20), Avon and Somerset Constabulary’s Chief Constable Andy Marsh and police and crime commissioner (PCC) Sue Mountstevens said: “For the past seven months all three partners have been working to revise the terms of the collaboration as recommended in the independent reviews. Sadly, we’ve been unable to reach a consensus on the detail of these arrangements.

“Unfortunately, we have not been able to reconcile the need highlighted by the reports to improve the effectiveness of the collaboration with our partners’ requirements to retain control of assets and staff in their areas, therefore leaving us with no option but to withdraw from the Tri Force Specialist Operations collaboration.”

They added: “Working together with our neighbouring forces and with other partners makes absolute common sense. It shares our expertise, training and costs, however, it has got to work in the interests of all parties, for our staff and residents and where it is efficient and effective to do so.”

Avon and Somerset Constabulary announced in April that it intended to withdraw from the alliance in April 2019 unless a revised structure could be agreed, although Ms Mountstevens said last month she hoped a new alliance for firearms delivery could be “finalised soon”.

And in October, Gloucestershire PCC Martin Surl said they would also terminate the arrangement in April 2019, just ten days after West Mercia Police withdrew from its alliance with Warwickshire Police.

Wiltshire PCC Angus Macpherson said the tri-force collaboration began “as a way of providing roads policing, armed response and police dogs more efficiently by sharing resources”.

“Some 18 months ago, we in Wiltshire, along with our Avon and Somerset and Gloucestershire colleagues, felt that the time had come to review how well the collaboration was working.

“In April this year, Avon and Somerset gave notice that it intended to withdraw from the tri-force collaboration from April 2019 unless there was agreement on a revised structure. At this time, the three commissioners and chief constables agreed that roads policing and dogs should revert to local control from April 2019.

“The proposal in relation to armed response was that, in order to make the new structure work effectively, direction and control of armed response policing in Wiltshire must pass to the chief constable of Avon and Somerset Constabulary.”

However, Mr Macpherson said he was “unable to accept that proposal” as it ran counter to his “strong belief in local accountability”.

“I believe that if a firearms incident occurs in Wiltshire, it is right and proper that the chief constable of Wiltshire should be accountable to me; just as I am accountable to the people of Wiltshire and Swindon,” he added.

Mr Macpherson said he had been briefed by the force on what a Wiltshire specialist operations structure would look like, and how much it would cost.

“To ensure operational resilience, we will need up to an additional 24 police officers at an estimated annual cost of £1.3 million. Although that is an extra cost, recruiting an additional 24 officers dedicated to Wiltshire Police will bring considerable benefits for the people I represent.”

Mr Marsh and Ms Mountstevens said they will continue to work closely with their neighbouring forces on other successful collaborations, such as major crime, forensics and counter terrorism, and “will support each other across all areas of policing when possible”.

“We are committed to protecting the communities of Avon and Somerset and are confident residents will not notice any difference to the level of service provided to them,” they added.

“Local policing continues to be protected and is not affected by this collaboration and the changes that will take place. Our priority remains to safeguard and enhance the front line of policing within Avon and Somerset.”

Mr Macpherson said the three forces will continue to train together at the jointly-owned, Black Rock firearms training centre at Portishead “with a single, consistent approach to tactics and use of weapons, in line with the College of Policing training framework”.

Gloucestershire PCC Martin Surl said he was “disappointed” that Avon and Somerset Constabulary felt the need to withdraw from the collaboration.

“We agreed to the return of the dogs and roads policing units back to local control following a decision by Avon and Somerset police to withdraw from the existing Tri-Force structure by 1 April 2019. But we had hoped to strengthen the Tri-Force arrangement around armed response with Avon and Somerset and Wiltshire working under a single joint command,” he said.

“Only last month, the chief constable and I met with the other two PCCs and chief constables to consider a number of different options, but sadly it wasn’t possible to reach a consensus which met the needs of all three forces.

“I regret that those discussions have now been terminated by the decision of Avon and Somerset to withdraw entirely from the arrangement they had with us and Wiltshire.

“As a force that borders six other police forces, it has always been my position that we should have effective collaboration with all neighbouring forces, totally interoperable with each other, so that in the event of a crisis, the nearest car attends irrespective of borders.

“All Gloucestershire Tri-Force officers and staff will come back under the sole command of our force from April 2019 and Tri-Force Specialist Operations will no longer exist from date.”